Improvement in chills for casting toothed-gear



illttcd giclee strat ijiiiicr.,

ar.. Davis, or can/fron, onto.

Leners Patent No. 102,781, ma May io, 1ero.

IMPROVEMENT 1N cfr-nnss ron caserne 'momen-GEAR.

The Schedule referred to in these Letters Patent andmaking part oftle same.

To all whom it may concern.- Y

smoother than they would he if cast in sand, as hereto y fore done.

In the accompanying drawings f Figure 1 presents a vien'vv of a toothed wheel, to which reference will he made in illustrating my methodl of casting.,

Figure 2 is a top vieu' of my chill-die.

Figure 3 is a like vieur of a Wheel-pattern, such as may he used m my method of' casting.

Figure 4 is a perspective view of the wheel-pattern lying in the bottom part of the molding-laslL Figure 5 is a vertical sectional'vicw of the top and bottom parts, together, inclosiug the wheel-pnttern as in the act oi' molding, the section being aslcut hy the plane indicated by the red lines fm n, fig. 4.

Figure ti is a perspective view of the impression made hy the wheel-pattern B inthe 'sand in the lower half ot' the ilask, and of the chill-die A placed in position for use after the removal of the wheel pattern. f

Figure 7 shows a vertical section made by the plane indicated hy the red lines xy, fig.v 5, through the tlaslr, chill-die A, and the wheel, after the cast has been made.

As theordinary flask is used, no further description of that is-necessary.'

The wheel-pattern B is made with the hub and arms of the wheel of the forms and dimensions desired, but the' depth through the rim should he made in proper proportions to that of the chill-die A, yet to be described, and should have a snliicient draft on its outer cilcumterence to insure its easy removal wit-hout warring its impression in the sand. j

.The chill-die, as shown in lig. 2, is the web or rim of a wheelwithout huh or arms, ln ving exactly the same thickness as the rim of the wheel-pattern B, and the; same circumference and draft, so that when the wheelpattern Bis removed this die A may take its place in the mold, `but its inner circumference is so'formed as to be the exact counterpart of the wheel that is to he cast, except that a due allowance'should he made for the shrinkage ofthe metal of the wheel in cooling, the

indent-ations d in the, chill-die corresponding to the teeth o. of the wheel C, and the teeth b of the die corresponding to indent-ations l1 between the teeth ofthe wheel C. l Carel should be taken to have the rim of the chilldie deep enough to have sufficient strength and stiffness, so as not to be sprung out of shape, and care, Y Y also should he taken that the teeth of the wheel should be as ivide at their bases asat their pitch-line, and that the pla-ne ot' their flasks Vshall not pass through the axis ofthe wheel, but at sue-h a distance therefrom asto secure their proper form and their proper radiahdirectien with reference to the axis, so that, 'when the lmetal of the chill-die shall chill the metal of the wheel east, the latterv shall shrink from the former equably at allpoints. The dieQin such case, will not be strained or injured.

The red lines c c, in :ligs.1-'and2,indicate what is w here meant;

The process of casting according to method is easily understood from what has been shown. Y v

After the wheel-pattern has been cast in the mold so as to leave its impression, itis removed from Athe iiask, and if the melted metal were then poured in, We would have a cast of that pattern; hut, in order to have teethY ot' the desired form cast to theA wheel, the die A, with teeth of any form or dimensions desired, is placed'in the mold after the wheel-pattern has left its impression, and, of course, it fills the moldso made from the outer circumference ofthe chill-die to its inner circumference, and then the melted metal is poured into the mold and the toothetbu'heel, of the form and dimensions desired, is cast.

rlhe surfaces of the teeth are chilled and hardened by the metal of the chill-die, and are perfectly smooth if the surface of the die' is so, instead of being soft and rough, as they would be' it' cast in the sand.

It is scarcely necessary for nie to assert how much more durable such hardened teeth willbe, nor how much such smoothness will conduce to their durability, besides making much less noise while in use.

I ,am aware that plain chilled rims or tires for' wheels have heretofore been east kin revolving metal`4 lic molds by theraid of centrifugal force, and I am also aware that plain chilled rims have been heretofore used in the cast-ing. of ear-wheels,.and so formed, as merely to aid in forming one or two lianges upon such wheels; but no such chill-die to form, harden, andrender smooth the teeth or eogs upon wheels has heretofore heen in use, and, more especially, has no sucli chill-dic as mineever heen used in connection with a wheel-pattern and common flask as 1 have done it:

Having fully described my invention,

my improved What I claim as new, Letters Patent. lsl 1. The described chill-die, when detached and removable into-aud out of molding-flasks at pleasure, and so constructed as to give the desired form to teeth or cogs upon and as parts of wheels, and at the same time to chill, harden, and render smooth the surfaces of such teeth or vcogs, substantially as above set forth.

2. Chilled tooth-gear,when cast by the above-deand desire to secure by scribed process, substantial] article of manufacture.

y as set fortl|,as a new Witnesses:

Jon ABBOTT, E. W. BEEBOUT.

R. T. DAVIS. 

